Pneumatic lubricant compressor



Dec. 22,A 1931.

Filed Sept. 15. 1928 2 Sheets-Sheet 2 QNN NNN, B {4|} l i mw 7/ @o A NENN QN mm. m6 @s QQN ummm @www ,ww ma, wm.

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Patented Dec. 22, 1931 UNITED STATES NORMAND W. MORSE, 0F CHICAGO,IILINOIS, ASSIGNOR T0 ALEMIT'E CORPOIR'A'IRN,` OF l PATENTl OFFICE 1CHICAGO, ILLINOIS, A CORPORATION 0F DELAWARE PNEUMATIC LUBRICANTCOMPRESSOR Application led September 15, 1928. Serial No. 306,165.

Myinvention relates, generally, to lubricating apparatus and moreparticularly to pneumatically operated lubricating compressors for usein forcing heavy greases to bearings under high pressure.

It is an object of my invention to provide an improved pneumaticallyoperated lubricant compressor which is light in weight and thus readilyportable, which is of extremely simplified construction, and which will0pcrate satisfactorily under various conditions of usage.

Another object of my invention is to provide improved plunger sealingmeans in a 15 pneumatically operated lubricant compressor.

i A further object is to provide an improved arrangement of cylindersand plunger-s in a compressor of this type.

Other objects will appear from the following description, 'referencebeing had to the accompanying drawings, in which Figure 1 and Figure 1atogether constitute a plan view of my improved compressor with itsdischarge conduit and coupling;

Figure 2 is a central vertical sectional View taken on line 2-2 ofFigure 1; and

Figure 2a is a side elevation of the discharge conduit and coupler.

In the lubrication of crank pin and other large bearings on locomotivesand similar machines where the bearings are subjected to great stresses,it is desirable to use a very heavy grease as a lubricant. Ascustomarily employed, this grease is marketed in cylindrical stickswhich have, in the past, usually been inserted in the bearing hole andthen forced into the bearing. by screwing down upon a cap which isthreaded in the bearing hole. Diiculty has been experienced in the pastto handle this extremely heavy lubricant since enormous pressures arerequired. Thus, many attempts to lubricate bearings with this heavygrease lubricant by means of a compressor detachably connected to afitting screwed into the oil hole of the bearing have been unsuccessfuldue to the lack of a conipressor, capable of efficiently handling this.

heavy grease and forcing it into the fitting under theextremely highpressures necessary. The compressor which I have invented 1s ca- 18 isthreaded, the latter serving as a guide for feeding sticks of lubricantto the cylinder 12. The cylinder 12 has a discharge port 20 which leadsto a longitudinally bored passage 22, the forward end of which isconnectedby a duct 24 with the high pressure cylinder 14.

Plugs 26 close the openings necessary to permit drilling of the port 20,passageway 22 and duct 24. These plugs may readily be removed forcleaning these passageways connecting the low and high pressurecylinders.

A high pressure plunger 28 is reciprocable within the cylinder 14 andfits in a recess formed in the end of the low pressure piston 30, beingconnected thereto by a pin 32 which passes transversely through thepiston 30 and plunger 28. The piston 30 is provided with a diametricallydrilled hole 36 having countersunk n "-4 into which a suitable pin maybe inserted to hold the piston against rotation .moves to the right(Fig. 2) and during the leftward stroke of the piston permits the escapeof any air or lubricant which may have been trapped behind the piston.

The piston 30 has a stem 38 formed integrally therewith, the stemextending rearwardly through a bushing 40 which is threaded at the rearend of the cylinder 12. This bushing has a slightly tapered portion 42which forms a pocket around the stem 38 in which grease may collect andserve as a seal to prevent leakage of the lubricant between the bushingand the stem. The bushing also'has a plurality of radial ports 44 whichcommunicate with an 'annular pas* sageway 46 formed in the casting 6. Aplurality of openings 48 connect the passageway 46 with the atmosphere.A gasket 50 is used to seal the bushing in the cylinder 8.

An air piston 52,comprising a pair of pppositely facing cup leathers 54,a backing plate 56 and a pair of face plates .58, is secured upon thereduced end portion 60 of the stem 38 by means of a nut 62, suitableflat washers 64 and a lock washer 66 being interposed properly toposition the air piston on the reduced portion 60.

The casting 6 has a flange 68 at its top above the cylinder 8, theflange defining a passageway which communicates wlth the cylinder 8through a port 72. A valve body 74 is secured upon the flange 68 byscrews 76, the forward screws 76 serving also to hold an air defiectorangle 78. The valve body 7 4 has a port 80 communicating between thepassageway 70 and a cylindrical bore 82 at the forward end of the valvebody. A cylindrical bore 84, co-axial with and of slightly largerdiameter than the b'ore 82, is formed in the rearward end of the valvebody and 1s normally in communication with a suitable source of fluidunder pressure, such as compressed air, through an elbow passageway 86,the other end of which communicates with a nipple 88 adapted to beconnected with a hose.

' A differential piston valve comprises a piston 90 fitting inI thecylinder 82 and having a stem 92, and a relatively larger piston 94which is pinned to the stem 92 and has a rearwardly projecting stem 96.The stem 96 has a portion 98 of reduced diameter guided in a bushing 100threaded in the rearward end of the cylinder 84. A suitable thumb piece102 is threaded at the extremity ofthe end portion 98.

A spring 103 which is shorter than the distance between the pistons 90and 94 is confined in the cylinder 84 and has one end normally restingagainst the shoulder formed between the cylinders82 and 84. As thepiston valve is 'being returned from its leftmost position, itspiston'90 covers the port 80 for a short time and during thistimeairpressure is exerted on the lower side of the'plston 90,

forcing the piston tightly against theA upper lateral surface of thecylmder 82, causing. an appreciable increase in friction.

vThe spring 103 is of such length that it will abut against the piston94 while the piston 90 covers the port 80 and thus overcome theaforesaid friction.

.to the difference in effective areas of the pistons 90 and 94) will besufficient to return the piston valve to the position shown in Fig. 2. Aguard 104, semicircular in cross section,

. prevents damage to and accidental reciproca- 'ing t As soon aslthepis-` ton valve has moved to the right'suiciently l tion of the thumbpiece 102 and stem portion 98.

The cylinder 84 has a port 106 leading intov the rearward end of the aircylinder 8 and has an exhaust port 108 open tol the atmosphere. The endof the cylinder 8 is lclosed by a cap 110 threaded in the cylinder. 1The connection between the cap and cylinder is kept air-tight throughcooperation of a sharp cornered flange 112 with a beveled surface 114 onthe cap. The cap has a hollow hexagonal boss 116 by which the cap may bescrewed into the cylinder casting. A handle 118, having a hollow griportion 120 is secured to the cast-ing 6 by a p urality of fillister 8head cap screws 122.

A discharge conduit 124 is threaded at the discharge end of the highpressure cylinder y14, being locked to the cylinder casting by a nut126. The conduit member 124 forms 85 one half of a swivel connectionwith a pipe 128. The other half of the swivel is secged to the conduitmember 124 byl'a bolt 1 The pipe 128 is which carries a coupling member134, is in substantial alignment with the axis of the high pressurecylinder 14. The coupling is adapted to make a detachable connectionwith offset so that its outer end, 90

a suitable lubricant receiving fitting of the 95 general type shown at136 threaded into the `valve body 74 so as to supplylubricant for thepiston valves 90 and 94.

vlubricant receiving fitting screwed into the oil holeof the bearing tobe lubricated, and then pressthe thumb piece 102, thereby move. pistonvalves 90, 94 to the left and connecting the left-hand end of thecylinder 8- with the source of air under pressure 'by uncovermg the port80.. Air will then flow from the passageway 86 through the cylinder 84,the 'right-hand end of the cylinder 82; Y

port 80, passageway 70 and port 72 into the", l

cylinder Scand build up a pressure therein) which, acting upon thepiston 52, will draw the hlgh and low pressurey pistons 28 and 30 to theright. As -the low pressure piston passes the the stick of] grease andforce it through the port 20, passageway 22 and duct 24 to the highpressure cylinder 14, the duct 24 being at that time uncovered by theplunger 28.

The movement of the air piston 52to the 1 right will-be limited by theabutment of piston 30 with the bushing 40. During this movement of thepiston the air in the righthand portlon of the cylinder 8 'will escapethrough the port 106, theright-hand portion 130 l The operation of thecompressor is as folloo ort 16 it will cut off a portion of 120 of thecylinder 84 and the exhaust port 108. Upon completion of this stroke theoperator will release the thumb piece 102 permitting the valve to returnto the position shown in Figure 2, at lirst under the inuence of thecompression of the spring 103 and the air pressure (due to the fact thatthe area of the piston 94 exposed to air under pressure is greater thanthe corresponding area of the piston 90.), and later by air pressurealone as previously described.

As the valve moves to the right the compressed air in the cylinder 8 tothe left of the piston 52 will exhaust to the atmosphere through theport 72, passageway 70, port 80 and cylinder 82. The stream of exhaustair is deflected and dispersed by the angle 78. At the same time airunder pressure is admitted to the cylinder 8 to the right of the piston52 through the port 106 which will at that time be in communication withthe passageway 86 through the cylinder 84. The air under pressure behindthe piston 52 will thus force the piston, together with the plunger 28and low pressure piston 30, to the left, thereby expellin the lubricantwhich was previously force into the high pressure cylinder 14.

Since the effective area of the air piston 52 is very many times asgreat as the effective area of the plunger 28, the lubricant will beforced from the compressor under extremely high pressures. The diametersof the piston 52 and plunger 28 may, ofcourse, be varied to obtain anydesired discharge pressure.

The operation-above described may be repeated several times untilsuiicient lubricant has been forced into the bearing. The troughlikegroove 34 in the piston 30 collects grease which serves as a seal toprevent p-assage of further grease past the piston 30. If, however, somegrease should escape past the piston it will not interfere with theoperation of the compressor since it will be expelled through the port37. Any lubricant leaking between the stem 38 and bushing 40 will becollected and discharged to the' atmosphere through the ports 38, 48.

It will be observed that upon both the priming stroke and upon thedischarge stroke of the compressor the full pressure of the air isutilized since the air pressure need not overcome any force other than asmall amount of mechanical and -hydraulic friction. Valves, stuflingboxes, etc., which would tend unnecessarily to increase the frictionhave been eliminated, making the compressor very eilicient and durable.

The invention is capable of wide variation within equivalent limits andI contemplate such variation as may-be desirable or useful in theparticular adaptation of the invention shown, or in its adaptation toother devices. I do not restrict myself in any unessential mission portadjacent one end of said low pressure cylinder, and a passageway leadingfrom said end of said low pressure cylinder to said high pressurecylinder, the opening of said passageway into said high pressurecylinder being located at a point such that it will be uncovered by saidplunger at'the time when said lubricant admission port is completelycovered by said low pressure piston.

2. In lubricating apparatus of the class described, the combination ofthree axially aligned interconnected cylinders of progressivelyincreasing diameter formed in an integral casting, a Wall between thelargest and the intermediate cylinders and a wall between theintermediate and the smaller cylinders, a `unitary member including apiston in the largest cylinder, a priming piston in the intermediatecylinder, and a plunger in the smallest cylinder, means for alternatelyadmitting a fluid under pressure to said largest cylinder upon oppositesides 0f the piston therein, a passageway connect.

ing the rear ends of said intermediate and said smallest cylinders,fluid adapted to operate said unitary member whereby said plunger willuncover the end of said passageway in said smallest cylindershortlyprior to the completion of the retractile stroke of said plunger, andmeans for supplying lubricant to said intermediate cylinder.

3. A pneumatically operated high pressure lubricant compressorcomprising a body having an air cylinder, a low pressure lubricantcylinder and a high pressure lubricant cylinder formed therein, a handleat one end of said body, a valve selectively operable alternately toadmit air under pressure to opposite ends of said air cylinder, a pistonin said air cylinder, a piston in said low pressure lubricant cylinder,a stem rigidly connecting said pistons, `means to prevent passage oflubricant from said low pressure cylinder to said air cylinder, apassageway within said body and connecting the rear ends of said highand said low pressure' cylinders, a 'high pressure plunger secured tosaid low pressure piston and operable near the end of its retractilestroke to uncover the outlet end of said passageway and during the majorportion of its pressure stroke to cover said end of said passageway, anda lubricant i lubricant cylinder formed therein, a handle at one end ofsaid body, a valve selectively operable alternately to admit air underpressure to'opposite end of said air cylinder, a piston in said' aircylinder, a piston in said low pressure lubricant cylinder, a plungerreciprocable in said high pressure lubricant cylinder, means connectingboth said pistons and said plunger in axialalignment, means to preventpassage of lubricant from said low pressure cylinder to said aircylinder, a

-passageway within said body and connecting the rear ends of said lowand high pressure cylinders, the outlet end of said passageway in saidhigh pressure cylinder being adapted to be uncovered -by said plungernear the end of its retractile stroke, a plurality of openings in saidbody leading into said passageway, and removable plugs in said openings.

5. In a lubricant compressor, the combina.- tion ofa low pressurecylinder and a high pressure cylinder in substantial alignment, a istonin said-low pressure cylinder, a sohd plunger secured to said pist-onand operable in said high pressurecylinder, a filling opening near therear end-of said low pressure cylinder closed by said piston inaretractive position, the displacement of said low pressure piston inthisl position being substantially equal to the total displacement ofsaid plunger; A a discharge passageway leading from said end ofsaidcylinder to the rear end of saidl high pressure cylinder, a.,

piston rod secured to said piston, and an air pressure actuated pistonand cylinder, said air pressure actuated piston and thev piston in saidlow pressure cylinder being rigidly interconnected.

In witness whereof, I hereuntosubscribe my name this 12th day ofSeptember, I1928.

NORMAND W. MORSE.

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